I am a photographer....just to let you know..not all photographers know what a headshot needs to look like and portray for acting/modeling. It also depends on where you are. New York casting agencies/agents/ect like something a little bit different than those in say California or Atlanta. Your photographer needs to know where you plan on suceeding and also needs to know what those different looks are.  Sure you can get anyone to take a head shot, but you need someone who really KNOWS the business, not just someone cheep looking for experience if you really want your photo to pop out and catch the eye of agencies/casting agents. Where are you?